Re: [PATCH net v4 0/3] Fix large frames in the Gemini ethernet driver

[Paolo Abeni]

On Thu, 2023-11-09 at 12:50 +0200, Vladimir Oltean wrote:
> On Thu, Nov 09, 2023 at 10:03:11AM +0100, Linus Walleij wrote:
> > This is the result of a bug hunt for a problem with the
> > RTL8366RB DSA switch leading me wrong all over the place.
> > 
> > I am indebted to Vladimir Oltean who as usual pointed
> > out where the real problem was, many thanks!
> > 
> > Tryig to actually use big ("jumbo") frames on this
> > hardware uncovered the real bugs. Then I tested it on
> > the DSA switch and it indeed fixes the issue.
> > 
> > To make sure it also works fine with big frames on
> > non-DSA devices I also copied a large video file over
> > scp to a device with maximum frame size, the data
> > was transported in large TCP packets ending up in
> > 0x7ff sized frames using software checksumming at
> > ~2.0 MB/s.
> > 
> > If I set down the MTU to the standard 1500 bytes so
> > that hardware checksumming is used, the scp transfer
> > of the same file was slightly lower, ~1.8-1.9 MB/s.
> > 
> > Despite this not being the best test it shows that
> > we can now stress the hardware with large frames
> > and that software checksum works fine.
> > 
> > Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
> > ---
> 
> Thanks for being persistent with this! I hope we didn't miss today's
> "net" pull request :)

I fear this is a bit too late for today's PR. I hope it should not be a
big problem, since we are very early in the release cycle.

Cheers,

Paolo